The present invention relates to baggage conveyor systems, such for use in a transportation terminal. More particularly the invention concerns drive mechanisms and configurations for facilitating various radii of the drive mechanisms.
In most airports, particularly high traffic facilities, baggage handling involves an extensive array of conveyors that carry luggage, packages, and other items, hereinafter collectively referred to as luggage, from various sources to various destinations throughout the airport, including luggage carousels for incoming luggage. A typical incoming luggage system includes a conveyor for transferring incoming luggage from an airplane to a conveyor surface of the carousel.
The carousel typically has an oval shape and includes overlapping pallets that move luggage around the oval shape, with each pallet traveling a complete revolution around the oval. The pallets are driven by a drive mechanism that may be a central mechanism or a modular mechanism. An example of a modular drive mechanism is provided in U.S. Pat. No. 7,621,392 to Langsdorf et al., where a motor rotates a drive wheel that is configured to come in contact with a drive chain connected to pallets in order to move the drive chain and thereby the pallets.
However, there is an interrelationship between load carrying capability of the drive chain (measured in lbs), and the frictional engagement between the drive wheel and the drive chain (measured in lbs) including a friction factor. The friction factor is in part based on material selections for the drive wheel and for the drive chain. For example, if the drive mechanism is designed and dimensioned to move 1500 lbs, with a friction factor of 0.5, the wheel must be capable of driving 3000 lbs (1500/0.5=3000). However, a single drive wheel capable of driving 3000 lb with a 0.5 friction factor may be expensive, noisy, and wear quickly. It is desirable for the drive mechanism to drive a large load, e.g., 1500 lbs, quietly and without excessive wear.
Once luggage makes contact with the conveying surface of the carousel, it continues to travel around the carousel until the luggage is picked by a person. The luggage capacity of the usual oval-shaped carousel is limited by the length of its perimeter. Therefore, airport terminals are designed to provide sufficiently large perimeters for the oval carousels to accommodate a large number of passengers. It may be desirable to provide a carousel with varying non-oval shapes, including inside and outside turns, in order to accommodate a large number of passengers in a terminal.
Therefore, it is desirable to provide improvements in carousel designs to meet challenges faced in an airport terminal.